Surfaces have been cleaned in a variety of ways including blasting the surface with a media blasting devices using a cryogenic material or media such as carbon dioxide particles or pellets. Media blasting devices eject the carbon dioxide pellets or particles from a media blast nozzle with a blasting or moving stream of air.
Carbon dioxide blasting systems are well known, and along with various associated component parts, are shown in U.S. Pat. Nos. 4,744,181, 4,843,770, 4,947,592, 5,018,667, 5,050,805, 5,071,289, 5,109,636, 5,188,151, 5,203,794, 5,249,426, 5,288,028, 5,301,509, 5,473,903, 5,520,572, 5,571,335, 5,660,580, 5,795,214, 6,024,304, 6,042,458, 6,346,035, 6,447,377, 6,695,679, 6,695,685, and 6,824,450, all of which are incorporated herein by reference.
Typically, particles, also known as blast media, are provided in a uniform size and fed into a transport gas flow to be transported as entrained particles to a blast nozzle. The particles or pellets exit from the blast nozzle with high velocity and are directed toward a work piece or other target (also referred to herein as an article). Particles may be stored in a hopper or generated by the blasting system and directed to the feeder for introduction into the transport gas. One such feeder is disclosed in U.S. Pat. No. 6,726,549, issued on Apr. 27, 2004 for Feeder Assembly For Particle Blast System, which is incorporated herein by reference.
Carbon dioxide particles may be initially formed as individual particles of generally uniform size, such as by extruding carbon dioxide through a die, or as a solid homogenous block. Within the dry ice blasting field, there are blaster systems that utilize pellets/particles and blaster systems which shave smaller blast particles from blocks of dry ice.
An apparatus for generating carbon dioxide granules from a block, referred to as a shaver, is disclosed in U.S. Pat. No. 5,520,572, which is incorporated herein by reference, in which a working edge, such as a knife edge, is urged against and moved across a block of carbon dioxide. These granules so generated are used as carbon dioxide blast media, being fed introduced into a flow of transport gas, such as by a feeder or by venturi induction, by a feeder/air lock configuration, and thereafter propelled against any suitable target, such as a work piece.
It is known to manufacture dry ice pellets/particles at a central location and ship them in suitably insulated containers to customers and work sites, whereas blocks of suitably sized dry ice are not readily available.
While several systems and methods have been made and used for a media blasting nozzle, it is believed that no one prior to the inventors has made or used the invention described in the appended claims.